Slushy Transmission after service

[TCCBass]

I know my transmission is getting a little weak. It's been shifting fine to 1-2, then a little soft to 3-4. So, I had the transmission serviced and a new (updated) modulator put on. Now it's REAL slushy when the car gets warm. All the vacuum seems to be fine, if anything it may be getting too much.
The mechanic as well as many other's I've spoken to says about 175-180K is about normal for these transmissions. But I thought it would go pretty gradually. Are there any adjustments that would cause this to go pretty quickly? I'm going to have the mechanic look at it when I go by this afternoon. He said there was some debris in the pan, and that it would need one soon but was ok for now. He's done good work for me, and will rebuild it for $1200. I just don't have that to spend right now, and was hoping for another miracle.
Well, hey, it worked with the glow plug !